Display panel or portion thereof with a transitional graphical user interface



FIG. 1 is a front view of a display panel or portion thereof with a transitional graphical user interface showing a first image in a sequence of the new design;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof; and,

FIG. 5 is a fifth image thereof.

The subject matter of the present disclosure includes a process or period during which one image transitions into another. The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1-5. This process or period in which one image transitions into another image forms no part of the claimed design.

The outermost broken line rectangle depicting a display panel or portion thereof forms no part of the claimed design. The broken lines depicting two oval outlines and a small circular outline, and all broken lines inside these outlines, show portions of a graphical user interface and form no part of the claimed design. All other broken lines depict environment and form no part of the claimed design. 

CLAIM The ornamental design for a display panel or portion thereof with a transitional graphical user interface, as shown and described. 